The sweet zone

Consider the following graph, Figure 9-14. Radial loading on the shaft rises if the pump is operated too far to the left or right of the best efficiency zone. Another interpretation of the same concept is to say that the maintenance and problems rise when the pump is operated away from its BEP. Many pumps have a rather narrow operational window. These pumps can be very efficient if they are correctly specified and operated. This is discussed completely in Chapters 7 and 8 Pump Curves and System Curves.